Add length(::ProductSector) (#23)

Author: leburgel

src/product.jl

@@ -16,6 +16,7 @@ end
 Base.Tuple(a::ProductSector) = a.sectors
 
 Base.getindex(s::ProductSector, i::Int) = getindex(s.sectors, i)
+Base.length(s::ProductSector) = length(s.sectors)
 Base.iterate(s::ProductSector, args...) = iterate(s.sectors, args...)
 Base.indexed_iterate(s::ProductSector, args...) = Base.indexed_iterate(s.sectors, args...)
 

test/runtests.jl

@@ -60,6 +60,7 @@ end
         @test typeof(a ⊠ b) == I1 ⊠ I2
     end
     @test @constinferred(Tuple(SU2Irrep(1) ⊠ U1Irrep(0))) == (SU2Irrep(1), U1Irrep(0))
+    @test @constinferred(length(FermionParity(1) ⊠ SU2Irrep(1 // 2) ⊠ U1Irrep(1))) == 3
 end
 
 @testset "Issue that came up in #11" begin